Safety edge mechanism



H. M. NORMAN SAFETY EDGE MECHANISM Aug. 24, 1954 5 Sheets-Sheet 2 G.

Filed March 13, 1951 V V 24/ 4 W l I INVENTOR.

Aug. 24, 1954 H. M. NORMAN 2,687,455 SAFETY EDGE MECHANISM Filed March 13, 1951 5 Sheets-Sheet 3 FIG. I

FIG. 11

-i|'n Imam F INVENTOR.

H. M. NORMAN SAFETY EDGE MECHANISM Aug. 24, 1954 riiea March 15. 1951 5 Sheets-Sheet 5 INVENTOR.

Patented Aug. 24, 1954 I UNITED STATES PATENT OFFICE 2,687,455 SAFETY EDGE MECHANISM Horace M. Norman, Skokie, Ill. Application March 13, 1951, Serial No. 215,305 10 Claims. (Cl. 200-6143) This invention relates to a safety edge mechafrequently happe on st n ll tions of nism for use with power operated doors and parthis type. ticularly to safety edge mechanism for use with In another type of safety edge mechanism power operated elevator doors. which was developed prior to my invention, a

It is convenient and facilitates rapid operation perforated rubber plate is fastened so as to overto make doors power operated. In order that p t e leading edge o a door. The rubber p at persons do not become m ured by a power opercontains a small tightly d1 awn cable imbedded ated door and to prevent damage to obJects which n its lead edge w i h if d splaced by bu pmay become lodged in a doorway, certain proing, actuates the electric operating switch and tective devices have been developed prior to my causes the door to open. Thi p has a d invention to arrest the closure of the door vantage in that external fow c u d y a of motion of the door. When the rubber safety in order to displace the imbedded cable. A larger edge member is moved b k abo t l t than comfortable force is thus required to operto the door, the electric operating switch is actut thi typ of f ty e m ch nism when disated which in turn causes the doors to n, placed in the direction of motion of the door.

In some designs the safety edg me b r do With the foregoing considerations in mind the not extend far enough in advance of the doors to safety edge mechanism presented in the included accomplish its purpose. This no doubt is to try drawings Was Conceivedto minimize the effect of reducing the size of the Th primary object of my inventi n is t pr apparent door opening for the passage of persons Vide a 116W and novel Safety edge mechanism for operation (by means of an auxiliary electric Operation at a m switch) for the last few inches of travel as the A urther object of my invention is to provide after a predetermined time. If it is desired to hold the doors open by pushing the safety edge A still further object of my invention is to proback then the awkward effect will be experienced ide an fi ctiv an simpl od of r in some installations the safety edges are in line t ggzggi g if i jg iz g 3;: 322 2 8 3 5: Eg

' 1. A when the doors close the edges butt up bars as the doors upon which they are mounted against each other. In order that the doors do near thelr fully closed position, and thei eby prenot Open due to the safety edges bumPmg them vent bumping of the safety edge members against each other.

Another object of my invention is to eliminate the need for auxiliary switches used to render the safety edge inactive while at the retracted ing the edges inactive, as just described, introposition duC e great d sad age of not giving the Another object of my invention is to provide proper protection should a persons hand or foot a safety edge mechanism for use with elevator get caught between the doors as they are about doors in which a safety edge is mounted on a car to close. There is also the disadvantage of the door so as to provide protection to passengers safety edges bumping each other and eventually against being bumped by either the hall door distorting the shape of the rubber edges as so or the car door.

operation (by means of an auxiliary electric 45 Other objects and advantages will become apparent from the following description and the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the views- Fig. I is a general assembly side view illustrating the manner in which the safety edge mechanism is mounted for operation on an elevator car door.

Fig. II is a sectional end view of the assembly illustrated in Fig. I. The section is taken transversely through the center of the door opening.

Fig. III is a sectional detail view of the safety edge member and the safety edge holder. The section is taken along the line III-III in Fig. I and along the line III-III in Fig. IV.

Fig. IV is a detailed side view of the safety edge member and safety edge holder showing the mounting of the switch and the mountin of the compression springs.

Figs. V, VI, and VII are d1agrams illustrating the relative positions of the safety edge member, safety edge holder, and switch plunger when various conditions of external safety edge member.

Fig. VIII is a diagram illustrating a method of increasing the sensitivity of the electric operating switch plunger to lateral deflection of the safety edge member.

Fig. IX represents a plan, partially in section taken on the line IX--IX in Fig. I, which illustrates in detail the safety edge member, the top of the safety edge holder; and part of the top link arm.

Fig. X represents a plan partially in section, which illustrates in detail the bearing arrangement used in articulatively mounting the safety edge holder to the link arm. A partial section is taken through the center of the bearing.

Fig. XI illustrates one type of inertia compensating device for use on doors which open and close at extremely high speeds.

Fig. XII illustrates another type of pensating device.

Refer to Figs. I and II which illustrate a manner of mounting the safety edge mechanism upon an elevator car door. The doors I illustrated are of the center opening type in which the two car doors are adapted to open one to each side of the center of the car opening. The doors are carried by means of hangers 2 and rollers 3 upon the rail 4. The rail d is fastened rigidly to the car. In Fig. I, only a portion of the right hand door and its associated safety edge mechanism is illustrated and described as the parts may be symmetrical about the center of the car opening. A mounting plate 5 is rigidly fastened to the car door The safety edge holder 6 is linked to the mounting plate 5 by means of the link arms I and s. The link arms i and 8 are articulatively fastened to the mounting plate 5 by means of needle bearings at positions 9 and Id. The link arms I and 8 are also articulatively fastened to the safety edge holder 5 by means of needle bearings at positions H and [2. The distance between the bearings at 9 and II is made equal to the distance between the bearings at In and I2 and the distance between the bearings at 9' and ii) is made equal to the distance between the bearings at I! and i2 so that the safety edge holder 6 and the safety edge member 13 may move relative to the car door yet always remain parallel to the edge of the car door. The manner in which the safety edge inertia commember 13 is held by the safety edge holder will be explained in the description of Figs. III and IV. A tension sprin it is fastened to the extended portion of the link arm I. The tension spring I6 is also fastened to the mounting plate 5 by means of a screw and nut which may be adjusted for proper spring tension. A roller is is mounted on the extended portion of the link arm 5. Two stops it and I! are rigidly mounted on the door sill 18. The stop It engages the roller I5 as the car door l nears its fully opened position. Further movement of the car door toward its fully opened position causes the link arm 6 to rotate about its bearing at it, thus retracting the safety edge holder and safety edge member away from the door opening. A rubber bumper ii] (fastened to the mounting plate 5) is adapted to hit against the door stop II and limit the amount of travel of the door in the open direction. This insures against possible damage to the safety edge retracting mechanism. The rubber bumper I!) alsolimits the amount of rotation of the arm 8. Rubber bumpers 2i) and 2| also limit the amount of rotation of the link arms I and 3 respectively. A rubber roller 22 is mounted on a bracket 23 which is fastened to the rail i. An aluminum angle piece 2%, which is rigidly fastened to the safety edge holder 6 is adapted to hit against the rubber roller 22 and thus retract the safety edge member when the door nears its closed position. The safety edge member is thus retracted relative to the door when the door is at its open position and when the door is at its closed position. Retracting the safety edge member when the door is at its open position has the advantage of presenting a larger effective door opening for the movement of passengers and materials. Retracting the safety edge members when the doors are nearing their fully closed position prevents the safety edge members from butting up against each other and ultimately distorting the normal or free shape of the rubber edges, and does not require the safety edge to be rendered inactive to operation. Rubber covered flexible lead wires 25 extend from terminals on the car to an electric operating switch which is located within the safety edge holder.

Refer to Figs. III and IV. A stiff vertical back portion for the safety edge member consists of thin spring steel sheets 26 and wooden spacer strips 21 which are bonded with cement and riveted to each side of a light alloy T section 23. A leading resilient edge for the safety edge member consists of the rubber sheet 23 (about A; inch thick) which is extruded in a U-shape and cemented to the thin spring steel sheet 26. The stifi vertical back position of the safety edge member is displaced relative to the safety edge holder when the safety edge member is contacted by an obstruction; also the leading resilient edge of the safety edge member is displaced (relative to the safety edge holder) all along its length when contacted by an obstruction. Thus this type of safety edge member is displaced in its entirety as distinguished from the perforated rubber plate type (having an imbedded cable) which is displaced only locally at the place of contact when contacted by an obstruction. The body of the safety edge holder consists of twolong vertical steel sheets 36 and SI bent in the form shown and fastened together with screws. The steel sheets 30 and 3! are formed with inwardly bent flanges 32 and 33 which hold the light alloy T section. Cylindrical spacers 34 are provided which are located near the flanges 32 and 33 so as to assure proper and rigid spacing of the steel sheets Y tthe switch the side of the safety edge holder to permit access one of the flanges and to bear agains to the electric operating switch 3?. The electric 5 plunger thus operating the electric switch. It is operating switch 31 is adjustably mounted on thus seen that the safety edge member is easily ed in a trough 49 between the steel sheets 30 and to external forces which are oblique to the direc 3|. The trough 40 is spot welded to the steel tion of travel of the door.

sheet 3%. A similar compression spring is simi- Refer to Fig. VIII wh ch llustrates a method y m t d near the top of the safety edge of increasing the sensitivity of the switch plungei member and the function of the compression M to lateral deflection of the safety edge member springs is to bear against the light alloy T section as caused by an external lateral force such as 46.

- teral deflection of the other end of sprin 4i 2* fastened to a position fol a glven amount of (not shown) on in; 1 section is. This thin fiat safety e member y to e that t spring steel strip 41 thus supports the Weight of a? the T Sectlon 0f the outlier edge of the the safety edge member yet does not restrict the T section t d of f' the gen method of supporting th safety edge member in An end cover 48 is spot Welded to the steel sheet its holder is to have the fiat spring Steel strip so as to exclude the dirt from nside of the looped over one of the spacers 34 and have both safetydg'e d 7 A rubber Qmmet 49 P ends of the steel strip screwed 0r riveted to the vided 111 h p cover t for sage of he fl light alloy T section. The car door I is shown in 39 le lead wires 25.

a close at extremely high speeds, an inertia comthe car door very thm rubb-er 2$; pensating device may be necessaryto prevent the so as to safety edge member fi'om being d splaced {relaspan the grooves between the safety edge holder to the a e y i holder) due to ltspwn and the safety edge member; this rubber covering ertlathls h Fr s s Shown is also to be provided on the top and bottom; all F F to reffeal mertla compensatmg, s; this being for the purpose of keeping out dirt yet f F Wa 1s ,fastened the lever not restricting the movement of the safety edge which Is plvotauy mountsd 52 m on the member relative to the safety edge holder. Only Steel f The s i ii r l fi the strip on the back side is Shown, the others tened 3A1 55 to the light alloy T section on the being omitte so as to reveal clearly the arts a e edge member- Thearm ,541Sprovldedwlth that these rubber Strips Coven an indented step 56. The top end of the lever 52 Refer to Figs. V, VI and VII which. are dialatched to the arm a It bears h grams. The safety edge member 53 is adapted mldnted t Assume the door durmg its o precede the edge of the door 5 and Contact an clos ng operation to be accelerated so as to tend obstruction the door moves toward its closed g the safety edge member (due. l its 22 position. Fig. V illustrates the relative position i i i s normal of the parts when no external force is applied to WCTlght s.lmmtar.leously uiged m the safety edge memben The light n T same direction (due to its own inertia) and will tion 28 is shown pressed to its normal position gauge Che lever to about its fulcrum against the inwardly bent flanges 32 and 33 by bear agamst h indented 55 the compression springs 39. In this position the supplying a,c9unteract.lve fgorce to 9 m (115 li'ght alloy T section does not bear on the switch placement the safety edge membel' It 18 de- Flg' VI illustrates the relative position of the as practicable in order that a person who is in its Q a :35 'ut the wei ht 5! will have a very small movey t ehcms Switch Qpelatlon of t merit because the link 57 will lift the arm 54 over electric switch causes the electric motor which its inflamed stpp and release the lever F'V power operates the door to be reversed and hence Thus person by the Safety edge member' would not receive the additional shock force supto its open position. The ex rnal force 5 is parplied by the e t 54 allel to the direction of travel of the door and a leverage ratio as is practicable for the lever 52.

in the doorway. ihis results in the necessary Weight of 51 to per- Fig. VII illustrates the relative positions of the ed.

parts when an external force such as 46 is ap- Fig. XII is the same as that illustrated in Fig. XI except that the arm 58 is pivotally connected to the lever 59 by means of pin instead of being latched to the lever. Thus this type enjoys a much simpler construction but has the disadvantage of subjecting a person to a larger shock force when hit by the safety edge member.

All figures are substantially to full size scale except Fig. I and Fig. II which are approximately one eighth size.

Although I have illustrated and described certain specific embodiments of my invention, it will be apparent that numerous modifications might be made without departing from the scope of the invention. For instance the safety edge mechanism may be used with power operated doors other than elevator doors. It is therefore my intention that such scope be limited only by the terms of the appended claims.

I claim:

1. In a safety edge mechanism for use with a power operated elevator door of the type which a safety edge holder mounted on the door in a manner so as to be movable as a unit relative to and in the same direction as the door, a safety edge member held by said safety edge holder in a manner so as to be movable as a unit relative to said safety edge holder and in the same direction as the door; an electric switch mounted in a manner such that movement of the safety edge member relative to the safety edge holder causes the electric switch to be operated, said safety edge member adapted to precede the edge of the door and contact an obstruction as the door moves toward its closed position, and means for retracting the safety edge holder and safety edge member as the door nears its closed position.

2. In a safety edge mechanism for use with a power operated door of the type which moves rectilinearly to open and closed positions in a doorway; a safety edge holder fastened to the door; a safety edge member held by said safety edge holder; said safety edge member having a stiff vertical back portion to which is fastened a leading edge of resilient material such as rubber; said-leading edge of resilient material adapted to precede the edge of the door and contact an obstruction as the door moves toward its closed position; said safety edge member adapted to be displaced relative to said safety edge holder when contacted by an obstruction, said displacement being all along the length of the safety edge holder, said, safety edge member adapted to be displaced relative to said safety edge holder when subjected to an external force which may be parallel to. perpendicular to, or oblique to the direction of travel of the door; and an electric switch mounted in a manner such that displacement of said safety edge member relative to said safety edge holder causes the electric switch to be operated.

3. A safety edge mechanism for use with a power operated door of the type which moves rectilinearly to open and closed positions in a doorway comprising a safety edge holder fastened to the door, a safety edge member held by said safety edge holder, said safety edge member having a stiff vertical back portion to which is fastened a leading edge of resilientmaterial, said leading edge of resilient material adapted to precede the edge of the door and contact an obstruc tion as the door moves toward its closed position, a T section fastened to said stiff vertical back portion, said safety edge holder having a longitudinal vertically directed sheet on each of two sides, said sheets having inwardly projecting flanges, said T section being resiliently held against said inwardly projecting flanges, an electric switch mounted in said safety edge holder, said electric switch having a movable operating member, said T section to receive movement relative to said safety edge holder when the safety edge member is contacted and displaced by an obstruction, and said movement of said T section being transmitted to said movable operating member so as to operate the movable operating member.

4. A safety edge mechanism for use with a power operated elevator door of the type which moves on a guide rail to open and closed positions comprising a safety edge member, two arms each articulatively fastened to the door, each arm also being articulatively fastened to the safety edge member, said safety edge member adapted to be retracted on the arms from the leading edge of the door, a stop fixed relative to said guide rail, at least one of said arms being extended, and the extended portion of the arm adapted to engage said stop and retract the safety edge member as the door nears its fully open position.

5. A safety edge mechanism for use with a power operated elevator door of the type which moves on a rail to open and closed positions comprising a safety edge member, said safety edge member being movably mounted on the door, said safety edge member being movable relative to the door in the direction of travel of the door, said safety edge member adapted to be retracted from the leading edge of the door, said safety edge member having a stiff vertical back portion to which is fastened an edge of resilent material such as rubber, said edge of resilient material adapted to precede the edge of the door and contact an obstruction as the door moves toward its closed position, a stop fixed relative to said rail, and means carried by said safety-edge member adapted to engage said stop and retract the safety edge member as the door nears its fully closed position.

6. A safety edge mechanism for use with a pair of power operated center opening elevator doors of the type which move on a rail to open and closed positions comprising two safety edge members each carried by a safety edge holder, each said safety edge holder being movably mounted on its respective door, each safety edge holder being movable relative to its respective door in the direction of travel of its respective door, each safety edge holder with its respective safety edge member adapted to be retracted from the leading edge of its respective door, each safety edge member adapted to precede the edge of its respective door and contact an obstruction as the doors move toward their closed position, two stops fixed relative to the rail, and means on said safety edge holders engageable with said stops to retract said holders together with their respective safety edge members as the doors near their fully closed position.

7. The combination recited in claim 1; wherein the safety edge member is resiliently urged to its normal position relative to the safety edge holder by means of a spring; an inertia compensating device adapted to prevent the safety edge member from being displaced from said normal position due to inertia forces resulting from high speed operation of the door; said inertia compensating device including a weight fastened to a lever, said lever being pivotally mounted on said safety edge holder, and said lever being connected to said safety edge member.

8. The combination recited in claim 1, wherein edge member is provided with a stiff two sides, said sheets having inwardly projecting flanges, and said T section being resiliently held against said inwardly pro- 9. In a safety-edge mechanism for use with a power-actuated elevator door of the type which moves rectilinearly to open and closed positions, a safety-edge holder mounted on the manner so as to be movable as a unit relative to and in the same direction as the door, a safetyedge member held by said safety-edge holder in a manner so as to be movable as a unit relative to said safety-edge holder and in the same direction as the door, control means and means for retracting the safety-edge holder and safety-edge member as the door nears its closed position.

10. In a safety-edge mechanism for use with a so as to be movable as a unit relative to said safety-edge holder in the same direction as the door and also at an angle thereto in a horizontal plane, control means having a Number Name Date 1,896,309 Forman Dec. 13, 1932 2,019,456 Liebenberg Oct. 29, 1935 2,523,645 Bruestle Sept. 26, 1950 2,610,268 Hamilton Sept. 9, 1952 FOREIGN PATENTS Number Country Date 384,551 Great Britain Dec. 8, 1932 

